1. Field
The present invention relates to printed packaging film and its method of manufacture in which the completed film has printed information that is visible from either side of the film.
2. Background
In many types of packaging applications, the packager desires to place his product in a receptacle that carries informative or decorative printed matter that can be seen from either side of the package. For example, many types of foods are packaged in a pouch made from flexible packaging film wherein two sheets of film are sealed together along contacting marginal portions to define the area within which the food is packaged; in this type of package, it is necessary that each sheet of film be separately printed when it is desired to provide information visible from both sides of the pouch. This package construction must normally be made in the plant of the package manufacturer or convertor and shipped as an empty package to the packager who then hand-fills and seals the pouch in his own plant. The construction thus tends to be expensive and the filling and sealing operations are generally slow and can require a good deal of hand work.
Many packagers in the food industries, particularly the meat industry, utilize in-plant packaging machines which are fed with rolls of flat packaging film that is formed into the desired package and then filled with product before being completely sealed. The most widely practiced equipment of this type is the so-called form-and-fill equipment, wherein one web, generally called the forming web, is fed through suitable apparatus and formed into trays in which the product is inserted and a second web, generally called the flat web, is thereafter fed over the top of the tray and sealed about its periphery to enclose the product. This type of equipment has enjoyed widespread use because of its convenience and the economies resulting from the ability of the packager to form his own packages by loading the machines with flat roll stock packaging film. However, this type of packaging equipment is incapable of handling two printed films and bringing them into superimposition in such fashion as to register printing material on each film. Thus, the machines require that one of the films in the package be unprinted and that all the printing be on the second film, generally the flat web, of the package. This has made it impossible for the packager to pack his goods in a container which will have printed information visible from both sides of the package and he is, at least as we are presently aware, forced to buy finished empty pouches from a package manufacturer as discussed above when he desires to make this type of package.
There thus exists a need among some packagers for a packaging film construction which will enable them to make a package on their in-plant form-and-fill packaging equipment that can have printed information visible from both sides of the package; such packagers receive maximum benefits if they can accomplish such end by using flat packaging film that can be directly fed to their form-and-fill equipment.